SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Consolidation of Variable Interest Entities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost	$ 10,041,653	$ 9,623,119
Debt securities of consolidated trusts held by third parties	26,818,717	26,586,959
Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value	5,399,151	5,532,479
Investment Securities
Variable Interest Entity [Line Items]
Carrying value	5,248,715	4,918,931
Agricultural Finance
Variable Interest Entity [Line Items]
Borrower remittances	5,900	6,000
Unamortized discount	104,600	87,100
Consolidated VIE \| On-balance sheet
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost	1,761,355	1,432,261
Debt securities of consolidated trusts held by third parties	1,662,549	1,351,069
Consolidated VIE \| On-balance sheet \| Agricultural Finance
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost		1,432,261
Debt securities of consolidated trusts held by third parties		1,351,069
Consolidated VIE \| On-balance sheet \| Treasury
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost		0
Debt securities of consolidated trusts held by third parties		0
Consolidated VIE \| Operating Segments \| On-balance sheet \| Agricultural Finance
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost	1,761,355
Debt securities of consolidated trusts held by third parties	1,662,549
Consolidated VIE \| Corporate, non-segment \| On-balance sheet
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost	0
Debt securities of consolidated trusts held by third parties	0
Unconsolidated VIE \| On-balance sheet \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value	58,292	46,343
Maximum exposure to loss	58,015	45,952
Unconsolidated VIE \| On-balance sheet \| Investment Securities
Variable Interest Entity [Line Items]
Carrying value	3,880,960	3,676,555
Maximum exposure to loss	4,095,777	3,862,006
Unconsolidated VIE \| On-balance sheet \| Agricultural Finance \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value		46,343
Maximum exposure to loss		45,952
Unconsolidated VIE \| On-balance sheet \| Agricultural Finance \| Investment Securities
Variable Interest Entity [Line Items]
Carrying value		0
Maximum exposure to loss		0
Unconsolidated VIE \| On-balance sheet \| Treasury \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value		0
Maximum exposure to loss		0
Unconsolidated VIE \| On-balance sheet \| Treasury \| Investment Securities
Variable Interest Entity [Line Items]
Carrying value		3,676,555
Maximum exposure to loss		3,862,006
Unconsolidated VIE \| Off-balance sheet
Variable Interest Entity [Line Items]
Maximum exposure to loss	436,822	452,602
Unconsolidated VIE \| Off-balance sheet \| Agricultural Finance
Variable Interest Entity [Line Items]
Maximum exposure to loss		452,602
Unconsolidated VIE \| Off-balance sheet \| Treasury
Variable Interest Entity [Line Items]
Maximum exposure to loss		$ 0
Unconsolidated VIE \| Operating Segments \| On-balance sheet \| Agricultural Finance \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value	58,292
Maximum exposure to loss	58,015
Unconsolidated VIE \| Operating Segments \| On-balance sheet \| Agricultural Finance \| Investment Securities
Variable Interest Entity [Line Items]
Carrying value	0
Maximum exposure to loss	0
Unconsolidated VIE \| Operating Segments \| Off-balance sheet \| Agricultural Finance
Variable Interest Entity [Line Items]
Maximum exposure to loss	436,822
Unconsolidated VIE \| Corporate, non-segment \| On-balance sheet \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value	0
Maximum exposure to loss	0
Unconsolidated VIE \| Corporate, non-segment \| On-balance sheet \| Investment Securities
Variable Interest Entity [Line Items]
Carrying value	3,880,960
Maximum exposure to loss	4,095,777
Unconsolidated VIE \| Corporate, non-segment \| Off-balance sheet
Variable Interest Entity [Line Items]
Maximum exposure to loss	$ 0

Amount, after accumulated amortization, of debt discount.

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